Method and apparatus for handling an integrated load



Aug. 15, 1961 B. ULINSKI 2,996,205

METHOD AND APPARATUS FOR HANDLING AN INTEGRATED LOAD Filed Feb. 5, 1958s Sheets-Sheet 1 INVENTOR. BfO/Y/SLAl/S A (/4 "Y6K! Arro /vey 1961 B. l.ULlNSKl 2,996,205

METHOD AND APPARATUS FOR HANDLING AN INTEGRATED LOAD Filed Feb. 5, 19583 Sheets-Sheet 2 T5. EL

UH H HH INVENTOR.

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B. ULlNSKl 2,996,205

METHOD AND APPARATUS FOR HANDLING AN INTEGRATED LOAD Filed Feb. 5, 1958I I I q 3 Sheets-Sheet 3 BY W% ,4 TTO/PNEY Unite tates This inventionrelates to lift trucks and, more particularly, to lift trucks forlifting, transferring and depositing integrated or unit loads.

Heretofore, it has been the frequent practice to stack integrated loadson skids or pallets for handling by a lift truck. This practice hasseveral very considerable disadvantages, including the cost of thepallets or skids, as well as loss of space occupied by the dunnage inwarehouses and the like. Further, the consignee must either return thepallets, or if dunnage is used, he is required to pay the cost of thedunnage, and thereafter dispose of it. Accordingly, it has long been thedesire of those skilled in the art to develop means for handlingstacked, integrated or unitloads so as to reduce or eliminate dunnageand skids, and some considerable success has been achieved in a numberof industrial fields. Thus, this aim has been achieved to some extent byclamping goods laterally between clamping means attached to lift trucks.This method of handling has thus far been effective only where the goodsare of a crush-resistant nature, as in the case of cement blocks, forexample, for which purpose laterally moving forks were developedtorexert great force on the bottom course of the blocks to hold themtogether frictionally while lifting that course together with a loadstacked above it.

Obviously, this method of handling is ineffective for goods packed inpaperboard cartons, since any gripping force that will support theentire load on the lower course of cartons will crush the said lowercourse. Recently, it has been proposed that the supporting cartons belifted by flaps, separate or integral with the cartons, and turnedoutwardly in wing-like attitude so as to lie directly beneath portionsof the remainder of the load. The forks of the lift truck enter thespaces between the supporting cartons and, upon elevation, engage thewinglike flaps to lift the supporting cartons along with the remainderof the load. While this method of stacking represents an importantcontribution to the art, it has been exceedingly, difiicult to utilizeit practically. My invention covers a concept whereby I may effectivelylift a unit integrated load of the type outlined.

I have actually constructed a successfully operating and commerciallydesirable truck based on that concept.

In essence, my invention resides in the utilization of a lifttruckhaving a pair of vertically' movable forks, and means for first movingthe forks to a laterally spaced position to permit entry of the forksbeneath portions of an integrated load supported on spacedloadsupporting cartons having their upper lateral flaps turned outwardlyunder the load.

As a most important feature of my invention, I provide means for urgingthe forks towards one another with a predetermined limited forcesufficient only to bring the forks into engagement with the cartonssubstantially below the level of the flaps. The engagement of the forkswith the cartons is so light that the forks when elevated will slidealong the sides of the load supporting cartons until they engage theunderside of the flaps substantially at the line where the flaps extendfrom the cartons whereby the forks, upon being raised further, will liftboth the supporting cartons and the remainder of the, load.

As one means for urging the forks towards one another atent O and thesupporting cartons, I prefer to employ spring means in order to obtainthe required predetermined limited force. As another means, I utilize ahydraulic ram for spacing the forks laterally as well as for urging themtowards one another, using a pressure valvefor limiting the force ofboth with which the forks are pressed against the cartons.

As another feature of my invention, I provide equalizing means forallowing movement of one of the forks towards the other when movement ofeither of the forks is obstructed as by its engaging one side of a loadsupporting member. In this manner, the apparatus automaticallycompensates for irregularities in alignment of the supporting cartons.

I have thus outlined rather broadly the more important features of myinvention in order that the detailed description thereof that followsmay be better understood, and in order that my contribution to the artmay be better appreciated. There are, of course, additional features ofmy invention that will be described hereinafter and which will form thesubject of the claim appended hereto. Those skilled in the art willappreciate that the conception on which my disclosure is based mayreadily be utilized as a basis for the designing of other structures forcarrying outthe several purposes of my invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions as do not depart from the spirit and scope of myinvention, in order to prevent the appropriation'o-f my invention bythose skilled in the art;

An illustrative embodimentof the invention has-been chosen for purposesof illustration and description and is shown in the accompanyingdrawings forming a part of the specification.

In the drawings:

FIG. 1 is an elevational view of a truck embodying my invention;

FIG. 2 is an end view of a portion of the truck shown in FIG. 1illustrating the forks in normal position;

FIG. 3 is a view similar to FIG. 2, but showing the forks in spreadposition;

FIG. 4 is a perspective view of a portion of the truck illustrating myinvention being applied to a stacked ,unit load;

FIG. 5 is a bottom perspective view showing my invention applied to andliftingthe load illustrated-in 'FIG. 4; and

FIG. 6 is a perspective view illustrating a modified form of fork.

Referring to the drawings, and more particularly to FIGS. 1 and 2thereof, there is shown an-industrial truck 10 of the type having abattery compartment 11 adapted to supply power through a traction unit(not shown) to the drive wheel 12. The truck is provided with suitabletrailer and steering wheels 14 under the control of a manual steeringwheel 15 disposed opposite an operators seat 16. Other necessarycontrols are accessible by an operator seated in the seat 16.

The truck 10 is provided'with a pair of primary uprights 17 andsecondary uprights 19. The primary uprights 17 may be mounted on thetruck for tilting move-.

I shall hereinafter point out of this application.

A pair of back plates 21 and 22 are slidably mounted on the carriage 20in side-by-side relation and may be moved laterally towards or away fromeach other by a pair of horizontal rams (not shown) mounted on the rearface of the carriage.

Each back plate carries a pair of forks 24 for pivotal movement aboutaxes that extend parallel to the longitudinal axis of the truck. Theforks each include a horizontal member or tine 25 and a verticallydisposed crank member 26 extending upwardly from the inner end of themember 25. The crank members are mounted on the back plate by a pivot27, and are nosed inwardly towards each other at their upper ends, as at29.

Each of the back plates 21 and 22 has a forwardly extending boredprojection 30 secured to it for supporting a hydraulic ram 31 inupstanding relation to the projection. A securing bolt 32 passes throughthe bore in the projection and is threaded into the base of the ram. Therams each have the usual piston 34 and piston rod 35, as shown in FIG.2, but I also place a helical compression spring 33 in each ram betweenthe piston and the base of the ram to urge the piston rod intoprotracted position.

The free end of each piston rod 35 has a cross-arm 36 connected to it bya pivot 37, and the ends of the crossarm are connected through pivotpins 39 to one end of links 40, the other end of each of these links 40being, in turn, connected to the nosed-in portions 29 of one of thecrank members 26 by pivot pins 41.

While the horizontal members or tines 25 of my forks may be constructedin any desirable contour, I prefer to employ cylindrical tines with flatplates 42 supported on the tines by spaced circular collars 44 connectedto the tines by removable dowels 45 as shown in FIG. 6. This arrangementprovides a large, flat load supporting area, as well as sharp edges forcornering at the inner edges of the flaps.

In operation, to lift an integrated load stacked in the manner alreadydescribed, the back plates 21 and 22 are spaced laterally to the desiredpositions depending upon the size of the units constituting the load tobe handled. The piston rods 35 are then retracted causing the links 40to depress the nosed-in portions 29 of the crank members 26 therebypivoting the crank members about the pivots 27 to rock the tines 25 awayfrom each other to the position shown in FIG. 3. In this manner, thetines are laterally spaced until each pair of fork tines is adapted toreceive one or several aligned supporting cartons of an integrated loadbetween them, as shown in FIG. 4.

After the forks are extended beneath the full length of the load, thefork spacing pressure on the rams is released allowing the springs 33 toraise the pistons 34 to move the forks in a direction towards each otheruntil they abut the sides of the load supporting members or cartons 46.At this point it is important to note that the means for moving theforks towards each other, such as the springs 33, are so selected orarranged that they exert a predetermined limited force sufficient onlyto bring the forks into sliding relation with the sides 47 of the loadsupporting members.

The carriage 20 may then be elevated relatively to the secondaryuprights 19 that may also be elevated for added lift if desired. Theforks will slide upwardly relatively to the sides of the load supportingmembers until they engage the underside of the carton or carrying flaps49, whereupon the supporting members are lifted along with the remainderof the load, as shown in FIG. 5.

Because of the linkage arrangement between the piston rods and theirrespective crank members, should movement of one of a cooperating pairof forks be obstructed by one side of the supporting members before theother fork engages the opposite sides of those members, the cross-arm 36will rock about the pivot 37 tilting upwardly the particularcontribution on the side of the unobstructed fork to permit that fork tocontinue movement towards the load while .the obstructed fork ispermitted to remain in its obstructed position without exerting anygreater force upon the sup porting members than is provided by itsrespective spring 33.

From the foregoing description, it will be seen that I have provided anindustrial truck for palletless handling of an integrated load stackedupon supporting members constituting a part of the load itself. It willfurther be seen that I have also provided means for urging the forks ofmy truck together with a predetermined limited force so as to slidinglyengage the sides of the supporting members without damaging them. I havealso provided equalizing means for allowing movement of one of the forkstowards the other when movement of either is obstructed by itsengagement with one side of a load supporting member.

I believe that the construction and operation of my novel fork will nowbe understood, and that the advantages of my invention will be fullyappreciated by those persons skilled in the art.

I claim:

1. An industrial truck for lifting an integrated load of the class inwhich cartons are stacked on spaced load supporting members thatconstitute part of the load and have wing-like portions extending underthe remainder of the load, comprising a carriage, means on said truckfor moving said carriage vertically, a pair of forks, means supportingsaid forks on said carriage to move vertically therewith and also forlateral movement relatively to one another, a ram on said carriage,means through which said ram when actuated moves said forks away fromone another to laterally spaced positions to permit entry of said forksbeneath portions of the load supported on the spaced load supportingmembers, surfaces on said forks for sliding engagement with the sides ofthe load supporting members, spring means yielding when the ram movesthe forks and effective when the ram is not actuated to urge said forkstowards one another to bring said fork surfaces into engagement with thesides of the load supporting members, said spring means constructed toexert a predetermined limited force enabling said fork surfaces whileengaged with the sides of the load supporting members to slide thereonupon elevation of said forks with said carriage until said forks engagethe underside of the wing-like portions, an equalizing lever throughwhich said spring acts when urging the forks toward one another, andmeans connecting each end of the lever to one fork to enable the springto move one of said forks towards the other of said forks when movementof said other of said forks is obstructed as by its engaging one side ofa load supporting member.

2. An industrial truck for lifting an integrated load of the class inwhich upper cartons are stacked on lower load supporting cartons or thelike that constitute a part of the load and that "have opposed sidesoffset from the sides of the upper cartons to leave overhanging bottomsurfaces on said upper cartons, said lower cartons or the like havingwing portions extending from their opposed sides laterally under saidoverhanging bottom surfaces of the upper cartons, comprising avertically moving load carriage, a pair of forks mounted for movementlaterally toward and away from one another on said load carriage andadapted for entry beneath said Wing portions of the lower cartons, saidforks having side surfaces that are formed for sliding on the opposedsides of said lower cartons when in contact therewith, mechanismconnected to said forks and effective when the forks have enteredbeneath the wing portions of the lower cartons for moving said forks ontheir mounting toward the opposed sides of those cartons, and saidmechanism including power means exerting a predetermined limited forcesufficient to bring the side surfaces of the forks into contact with thesides of the lower cartons without substantial clamping of the cartons,so that an upward movement of the load carriage will act by sliding theforks on the lower cartons to place the forks in lifting contact withthe wing portions at points that are juxtaposed to the sides of thelower cartons.

3. An industrial truck for lifting an integrated load of the class inwhich upper cartons are stacked on lower load supporting cartons or thelike that constitute a part of the load and that have opposed sidesoffset from the sides of the upper cartons to leave overhanging bottomsurfaces on said upper cartons, said lower cartons or the like havingWing portions extending from their opposed sides laterally under saidoverhanging bottom surfaces of the upper cartons, comprising avertically moving load carriage, a pair of forks mounted for movementlaterally toward and away from one another on said load carriage andadapted for entry beneath said Wing portions of the lower cartons, eachfork having an upper lifting surface for lifting engagement with a Wingportion, and also a side surface in opposed relation to the other forkand formed for sliding one side of said lower cartons when in contacttherewith, mechanism connected to said forks and effective when theforks have entered beneath the wing portions of the lower cartons formoving said forks on their mounting toward the opposed sides of thosecartons, and said mechanism including spring means exerting apredetermined limited force sufficient to bring the side surfaces of theforks into contact with the sides of the lower cartons withoutsubstantial clamping of the cartons, so that the forks by sliding on thelower cartons when the load carriage moves upwardly will place theirlifting surfaces in contact with the wing portions at points that arejuxtaposed to the sides of the lower cartons.

4. The method of handling an integrated load of the class in whichcartons are stacked on a load supporting member that constitutes a partof the load and that has opposed sides offset from the sides of thestacked cartons to leave overhanging bottom surfaces on said cartons,said load supporting member having Wing portions extending from itssides laterally under the overhanging bottom surfaces of the cartons,comprising driving a fork carrying industrial truck to a positionopposite the load, moving the forks and the truck to place the forksbeneath the overhanging carton surfaces, moving the forks toward oneanother with a predetermined limited force suflicient only to bring theforks into contact with the opposed sides of the load supporting memberwithout substantial clamping of the member, sliding the forks upwardlyon the sides of the load supporting member so that said member guideseach fork until it moves into a lifting position at the juncture betweenthe corresponding side and wing portion of the load supporting member,and moving the forks further upwardly whereby to lift the loadsupporting member and cartons through forces applied to the wingportions at points that are juxtaposed to the sides of said member.

5. The method of handling an integrated load of the class in whichcartons are stacked on a load supporting member that constitutes a partof the load and that has opposed sides offset from the sides of thestacked cartons to leave overhanging bottom surfaces on said cartons,said load supporting member having wing portion extending from its sideslaterally under the overhanging bottom surfaces of the cartons,comprising driving a fork carrying industrial truck to a positionopposite the load, moving the forks and the truck to place the forksbeneath the overhanging carton surfaces, applying to said forks a forceto move the forks toward one another and into contact with the opposedsides of the load supporting member, while limiting said force to apredetermined value that will not efiect substantial clamping of themember and that will allow the forks to slide on the sides of themember, moving the forks upwardly while applying said predeterminedlimited force to maintain the forks in sliding contact with the sides ofsaid member, said sides of the member thereby guiding each fork into thejuncture between a corresponding side and wing portion of the member,and moving the forks further upwardly whereby to lift the loadsupporting member and cartons through forces that are applied to thewing portions at points juxtaposed to the sides of said member.

References Cited in the file of this patent UNITED STATES PATENTS2,475,367 Avery July 5, 1949 2,509,023 Vogel et al May 23, 19502,601,933 Seagraves et a1. July 1, 1952 2,685,976 Ulinski Aug. 10, 1954FOREIGN PATENTS 132,932 Australia Dec. 12, 1946

